What 64 owners told NHTSA about the 2024 Kia Carnival Hev

Our 2024 Carnival has had a recurring engine oil leak that has required the vehicle to be left at the dealership 4 times for the same issue. Each time we get the van back the repair lasts about 1-3 weeks (depending on how often it's driven). Oil continues to leak from the engine area, creating risk of engine damage or a potential fire hazard if oil contacts hot components. The issue has not been resolved despite repeated repair attempts under warranty. The Carnival has 38,092 miles on it, and has been in the repair shop over 4 times. The 1st time it was put in the shop the van has 34,420 miles on it. Each time it has been left at the dealership for 9 - 17 days while the repairs were made. We have brought it to the same dealership each time and they have been very sympathetic and helpful. Not only does this issue cause the risks mentioned above, but it has ruined the concrete in my garage as well as added oil to the roadway which could cause an accident. I have all the repair orders from the first 3 repairs that I will attach. However I do not have thee current one because the vehicle is currently being repaired for the 4th time and I haven't received the finalized repair order documents. I can update this claim once the repairs are completed. I will be contacting Kia tomorrow and wanted to have a claim number started.

NHTSA ODI 11734153

My Kia vehicle has an ongoing engine oil leak that has not been properly repaired under warranty. The vehicle was taken to an authorized Kia dealership for diagnosis and repair of the oil leak. I was informed by the dealership that Kia engineers indicated that in similar situations the typical resolution is engine replacement. However, in my case, the dealership was instructed to attempt sealing the oil pan instead of replacing the engine. I was advised that if this repair did not resolve the issue, I could bring the vehicle back for further service. Unfortunately, the oil warning light has now returned on the dashboard, indicating the issue persists and the repair attempt was not successful. An unresolved engine oil leak presents a serious safety concern because loss of engine oil can lead to engine damage, stalling, or failure while driving. This creates a risk of unsafe driving conditions, especially when transporting passengers. My family relies on this vehicle for daily transportation, and the continued presence of the warning light makes the vehicle unreliable and concerning from a safety standpoint. In addition, the dealership has not provided a suitable loaner or rental vehicle large enough to accommodate my family while the vehicle is undergoing repair. This has created significant hardship as we do not currently have reliable transportation. The manufacturer should correct this defect properly and ensure the vehicle is safe to operate rather than attempt temporary or experimental repairs that do not resolve the root cause. The persistence of the oil leak after warranty repair raises concerns about the reliability and safety of the engine. I am submitting this complaint to document a potential engine defect that may pose a safety risk if engine oil loss leads to engine failure while the vehicle is in operation.

NHTSA ODI 11728723

"Continuous engine oil leak for 12 months. After 4 failed repair attempts, the dealer used liquid sealer instead of a gasket. This is a deceptive repair that creates a severe fire hazard. The leak is still active today, March 2026."

NHTSA ODI 11727626

Out of nowhere, we started our vehicle that was no more than a year old, and all of the emergency alert indicators on the dash came on. All of the warning lights in the dash. The power steering went out and would go from very stiff to very loose. the car would shutter and then drive normal for a few min and then slow way down without warning. Again, all dash warning lights and alarms would go off. This first appeared on [XXX], we took to the Kia service on Nov. 17, 2025, and it was been in the shop with no repair since that day and todays date is Jan, 12, 2026. As of today they still do not know what is wrong with the vehicle and have no end in sight. INFORMATION REDACTED PURSUANT TO THE FREEDOM OF INFORMATION ACT (FOIA), 5 U.S.C. 552(B)(6)

NHTSA ODI 11710508

I am submitting this complaint regarding my Kia Carnival. The vehicle has a recurring and dangerous problem where the engine suddenly jumps and, if I continue pressing the gas, it shuts off while driving. This has happened multiple times, including in the middle of the highway, creating a serious safety risk for myself, my passengers, and other drivers. I have taken the vehicle to a Kia dealership on multiple occasions, but they have not been able to identify or repair the issue. I also contacted Kia corporate, obtained a case number, and was told someone would follow up with me. Unfortunately, no one has ever called me back. This is an ongoing and unresolved defect that puts my family and the public in danger. I request that the NHTSA investigate this matter to determine if this is part of a larger safety defect in Kia Carnival vehicles. INFORMATION REDACTED PURSUANT TO THE FREEDOM OF INFORMATION ACT (FOIA), 5 U.S.C. 552(B)(6) Kia case number XXX

NHTSA ODI 11690165

Vehicle vents gasoline fumes into the passenger cabin causing drowsiness, headaches, and impaired cognitive function as well as exposure to a carcinogen. Vehicle has significantly high levels of CO2 inside the cabin at all times (2000-4000ppm) as well as TVOC and HCHO being higher than OSHA allows. Engine temperature gauge does not function properly and sliding doors have closed on myself and my children leaving bruises. If car were to be in an accident it would likely explode. Critical levels of CO2 have caused me to fall asleep while driving on several occasions including on the highway. I have brought car to Kia dealership in Tucson, AZ on 4 occasions, is currently back again for gas smell and high levels of CO2, with no resolution. Dealer manager and service team did confirm gas fumes in cabin and are currently using my CO2 monitor to test for CO2 levels. Vehicle component hasn't been inspected by police, insurance rep., or others. There are no warning lights of any kind on any instance of these occurrences. Images will not upload- email or call.

NHTSA ODI 11671372

The contact owns a 2024 Kia Carnival. The contact stated that while driving at various speeds, the vehicle failed to properly accelerate while depressing the accelerator pedal. The vehicle was shuddering and vibrating while attempting to accelerate with the check engine warning light illuminated. The vehicle was towed to the dealer on several occasions, but the cause of the failure was not determined. The manufacturer was notified of the failure. The failure mileage was 3,500.

NHTSA ODI 11568435